Investigators said the dispatchers failed to properly notify EMS about the emergency, and that the supervisor didn’t ensure proper coverage.

“EMTs took forever to come,” said witness Megan Maloney. “I was like, ‘These kids are dying in front of you.’”

“It was a lot of people asking, ‘Where’s the ambulance?’ while the kids was laid out on the floor,” said witness Shakeea White.

An FDNY supervisor and three dispatchers were suspended following the fire.

The 911 dispatch system also came under heavy criticism a year ago when Bloomberg was still in office, when there was a four-minute delay in dispatching an ambulance to an Upper West Side car accident where 4-year-old Ariel Russo was clinging to life.

Since 2004, when the city began a $1.3 billion, five-year upgrade project, the NYPD and FDNY have been defensive about the 911 system.

But Mayor de Blasio was not the slightest bit defensive on Monday.

“The more we looked at the 911 situation, the more troubled we got,” de Blasio said. “So we’ve brought this project to a dead stop.”

De Blasio revealed that a review by his aides has uncovered new risks – including problems with the technical design, systems integration, and project management – and so he decided to halt further development until a top-to-bottom assessment can be completed.

“The cost overruns alone suggest that something is fundamentally wrong,” de Blasio said. “I think this required a top-to-bottom review, and the Department of Investigation will be involved as well.”

There have been many kinks in the system — from calls being dropped, ambulances and fire trucks sent to the wrong location, and long delays.

But Bloomberg and Kelly repeatedly defended the new system, and demands for change fell on deaf ears, Kramer reported.

During the mayoral campaign and since taking office, de Blasio has often been a bitter critic of his predecessor, Kramer pointed out. But on Monday, he took a much less confrontational approach.

“I think there were a lot of warning signs over the years that weren’t heeded,” de Blasio said.

De Blasio said the 911 upgrade project is now years behind schedule and now $1 billion over budget. City Comptroller Scott Stringer said his audit division will also investigate possible lapses in management and financial control.